Using regular expressions in Go.

package main

import (
    "bytes"
    "fmt"
    "regexp"
)

var p = fmt.Println

func main() {
    // Basic regular expression match does not require compiling.
    match, _ := regexp.MatchString("p([a-z]+)ch", "peach")
    p(match) // => true

    // Normally you need to compile the regular expression.
    pchRegex, err := regexp.Compile("p([a-z]+)ch")
    if err != nil {
        panic(err)
    }

    p(pchRegex.MatchString("peach"))   // => true
    p(pchRegex.Match([]byte("peach"))) // => true

    p(pchRegex.FindString("peach punch"))              // => peach
    p(pchRegex.FindAllString("peach punch", -1)) // => []string{peach, punch}
    p(pchRegex.FindAllString("peach punch", 1))  // => []string{peach}

    p(pchRegex.FindStringIndex("peach punch")) // => []int{0, 5}
    p(pchRegex.FindStringIndex("plum fump"))   // => []int{}

    p(pchRegex.FindStringSubmatch("peach punch"))      // => []string{peach, ea}
    p(pchRegex.FindStringSubmatchIndex("peach punch")) // => []int{0, 5, 1, 3}

    p(pchRegex.FindAllStringSubmatchIndex("peach punch pinch", -1))
    // => [][]int{[0 5 1 3], [6 11 7 9], [12 17 13 15]}

    p(pchRegex.ReplaceAllString("a peach", "<fruit>")) // => a <fruit>

    in := []byte("a peach")
    out := pchRegex.ReplaceAllFunc(in, bytes.ToUpper)
    p(string(out)) // => a PEACH

    // MustCompile automatically panics if it fails.
    mustPchRegex := regexp.MustCompile("p([a-z]+)ch")
    p(mustPchRegex) // => p([a-z]+)ch
}

Sources

• Regular Expressions